Small correction:
Overall, I feel that young adults are mostly taught theoretically in their learning process which ALTERS the purpose of studying in learners' eyes. However, I believe that in order to improve THE quality of --- outcomes of THE educational system, arouse interest and experience team work, sufficient time should be dedicated to PRACTICAL skills.
("on-site" means physically at a location, and doesn't make sense here. The opposite of "in theory" is "in practice")
While this is technically correct, it is difficult to read. I would try to make more, shorter sentences. Some parts of your sentence are redundant. I know other languages use big words and long sentences, but this is not good practice in English today (maybe in literature, but not for technical or academic contexts, where the topic is difficult to understand).
Example:
Overall, I feel that young adults are mostly taught theoretically which alters the purpose of studying in learners' eyes. To improve the outcomes of the educational system, arouse interest and experience team work, sufficient time should be dedicated to practical skills.
But this is just style.